Overview relibc is a C standard library (POSIX-compatible libc) implementation written in Rust for Redox OS. It provides the standard C library interface while leveraging Rust’s safety guarantees under the hood.
relibc Repository View the relibc source code on GitLab
Key Features
POSIX Compliance Implements standard C library functions and POSIX APIs
Rust Safety Core implementation in Rust for memory safety
Linux Compatibility Provides compatibility with Linux applications
BSD Support Compatible with many BSD programs
Purpose relibc serves as the bridge between C/C++ applications and Redox OS:
Application compatibility : Allows running existing C/C++ software on RedoxPOSIX interface : Provides familiar POSIX APIs for developersSafe implementation : Uses Rust internally for critical operationsCross-platform : Works on both Redox and Linux (for testing)
Architecture relibc is structured as a hybrid implementation:
// External C API extern "C" fn open ( path : * const c_char , flags : c_int ) -> c_int { // Rust implementation calling Redox schemes // Provides safety while maintaining C compatibility }
Building with relibc Programs link against relibc automatically in the Redox build system:
[ packages ] relibc = {} # C standard library libgcc = {} # GCC runtime libstdcxx = {} # C++ standard library
Standard Library Support relibc implements most standard C library functions:
stdio
stdlib
string
unistd
// Standard I/O functions FILE * fopen ( const char * path , const char * mode ); int fprintf (FILE * stream , const char * format , ...); int printf ( const char * format , ...); size_t fread ( void * ptr , size_t size , size_t nmemb , FILE * stream ); size_t fwrite ( const void * ptr , size_t size , size_t nmemb , FILE * stream );
// Memory and process management void * malloc ( size_t size ); void free ( void * ptr ); void * calloc ( size_t nmemb , size_t size ); void * realloc ( void * ptr , size_t size ); void exit ( int status ); int system ( const char * command );
// String operations size_t strlen ( const char * s ); char * strcpy ( char * dest , const char * src ); int strcmp ( const char * s1 , const char * s2 ); void * memcpy ( void * dest , const void * src , size_t n ); void * memset ( void * s , int c , size_t n );
// POSIX system calls ssize_t read ( int fd , void * buf , size_t count ); ssize_t write ( int fd , const void * buf , size_t count ); int close ( int fd ); pid_t fork ( void ); int execve ( const char * path , char * const argv [] , char * const envp [] );
Device File Mapping relibc translates standard device files to Redox schemes:
// Standard device files mapped through relibc open ( "/dev/null" , O_RDWR); // Maps to null: scheme open ( "/dev/random" , O_RDONLY); // Maps to rand: scheme open ( "/dev/tty" , O_RDWR); // Maps to libc:tty open ( "/dev/stdin" , O_RDONLY); // Maps to libc:stdin
Porting Applications Many applications can be ported to Redox with minimal changes thanks to relibc:
Build with Redox toolchain
Use the Redox cross-compilation toolchain that links against relibc
Handle platform differences
Some system-specific features may need conditional compilation
Test compatibility
Test the application on Redox to identify any missing APIs
Redox provides source code compatibility with many Rust, Linux, and BSD programs through relibc.
Configuration relibc is part of the base system:
[ packages ] relibc = {} [ dependencies ] libc = "0.2" # Rust programs can use the libc crate
Cargo Integration The Redox build system includes relibc in its dependencies:
[ dependencies ] libc = "0.2" termion = "4" # Terminal library that uses relibc
Resources
relibc Repository Source code and development
Redox Book Documentation on porting applications
POSIX Compliance Supported POSIX features
Developer FAQ Common questions about relibc
Maintainer
Jeremy Soller (@jackpot51) Primary maintainer of relibc